Method of producing articles of glass



Sept. 16, 1952 w. KURZ 2,610,444

METHOD OF PRODUCING ARTICLES OF GLASS Filed July '7, 1949 A 7708M: Y5

the'glass by means orapressing tool.

Patented Sept. 16, 195 2 2,fil0,4,44-

DUCING narrows- 1 METHOD OF PR0 OF GLASS 'rreariiewnhum- Anton kamny'm, swear-m" Application June, 1949, Serial No. 103,489

In SwedenFebruary:-2,;' 1942 s'et itnj riitiiemw e90, aug st 8,1946

Patent expires February 2,1962

(Cree- ,49)

11 Claims.

Various methods, such-as jopalizih'giand'frosting, are known for reducing -the transparency-of glass. There are "also known various methods for increasing the refractivepowerof glass. Asa rule, reducing or the transparencyand increasingof the refractive power counteract each other, since glass which transmits .dif'fusedf lifeht-generally' appears rough ormilk-coloured; whereas glass with sparkling, light'refracti'on' fsu'ch't as faceted glass, is very transparent,';softhatobjects behind the glass can'b'e 'easily--discerned;although in a disfigured'shap'e:

The present vinvention is apontinuation-inpart of my copending applioation; Serialf'No. 518,101, filed J anuary l3,rl944,-; whichhas *been formally abandoned "and has "'for "its "object to render possible the production of articles ofjglass, particularly for lighting fixtures;- with" retained character of clear glass and having-an increased refractive power, the transparency -being; 1however, reduced to :suchanextent that -o'bje'ctsbehind the glass eanno't be discerned; sincefthe rays of light are distributed iin differentfdirections. Such articles f glass are especially well adapted vfor shades for-"lightingfixtures as the articles may be given "an attractive appearance and the material may-be treated to produce good artistic efiects. V

The method accordin to-the invention may be carried "out in various manners; for" instance-in, that the glass is poured or'roll'ed ln-such a rnanner in a heated statein a-mould-"being 'open'at the top and having confining edgesatfthe circumference, that the glassatthe circumference ofthe mould is givena contourwhich is main! tained in the final product without mechanical treatment, and in that the'glass' orrits upper side is formed, by pressing" enrolling, i-nto projecting portions, such as corrugated designs.-

The production of the article'of *g'las's may be; carried out'by pouringor rolling-"heated-viscous glass'upon a smooth or fancy-mould bottom consisting of-iron or-any other suitable material. Themould bottom is laterally confined by: an edge of Honor other suitable material, which: may be detachable" and has theshape and design desired for the articleto beprod-uced. The edge preferably-has the sameheig ht as'thethickness of the glass to be produced. The glasses spread or rolled toward the edge-so as tor give --th'e contour of the article the shape of the edgeof the mould. Then, the-desired design i's; formed in suitable tool; suchas a Thereby; a' glass' product profiled on one or both-sides is obtained; depending 11130111 7 stanti-ally round first.

Y shaped lateral edge being either substantially cirwhether a smooth or. fancy mould bottom is emc'ular orL-corrugated. "In order to :produce the cup+shape;ithe. glass treated'inathe'first mould is heatedtin. a furnace-and placed upon the second mould-having.theadesired shape. In this case, the glassamawsink into;.the1mould or pressed down into the mouldby: means of/a suitable tool without deteriorationoi the designs previously formed on'rthe isurifaoes qoftztheglass; r

mould lthe ggl'as's :visrgiven :designs on the lower In :castingror pressing the :glass ;in ,a mould, fins or thin edges :arelikely to :be formed especial- 1y-;at rthjeqedges :of the .mould; Such :fins can be 'eliminatedabysuitable heat treatment of the glass wherebyrto: melt :the; fins into the mass of the glass. Irivthis' way, "thefins are removed without anymechanical treatment which might result ;in disturbingzrefractive effects Themethod of :producing glass articles in accordance with the present invention consists in first forming the glass ;body;.-ina substantially plane 1 mould 'having; confining edges. .Inthis sideand by a certain-operationalso on the upper side.- The-designron the upper side has another generaldirectionrthan :the design ,on the lower side; The; glass is then-removed from the mould while still hot andris placedin: a -furnace in order to: be.- reheated.v The glass :body :removed from the mouldun'ust; noticool; belowj 350 0;; preferably not belowr-about 500"C'qbefore Y-it'is placed in "the furnace; and-,in-this furnaceit is heated so that thezupper side of itheglass reaches; a temiperatureiof about 1000? C.) The reheatedllass is thenremovedfrornthe furnace and is bent by means of thelgsecond mould.- ,During the reheating; the cz fins 1 or; thin: edges: formed; at the sides. of the glassiwhenivtreatedgin the first mould are meltedintoi thermassrof, the glass. At the same: time: all unevenness; of the glass surface isismooth'ed out; dueto thehigh temperature pre- 1 vailing.-;in-.the furnace -so that the glass; surface becomess-even and; gshiny-f It is ;preferable-;tokavoid sharp.- edges'; on the glass. 'Iheidesignsion the upper I and flower I face of :theglasszshohld, therefore, bewell rounded.

. Referringto :the :drawings inqwhieh are shown Figure 3 illustrates the same mould as FiglOi ure 1 in combination with a roller for producing thedesign on the upper side of the glass.

Figure 4 illustrates a sectional view of a sec- 7 nd mould for producing the final curved shape of the glass.

Figure 4a is a modification of the mould shown in Figure 4.

4- in the bottom surface of the body. In the modification shown in Figure 4a., the mould a is of concave shape so that the corrugated designs Ea will be of the same configuration. Thus, it will be seen that a glass fixture provided with ornamental designs on opposite sides thereof may be of any concave or convex'shape so as to reduce the transparency of the glass body.

Manifestly, a large number of images of the source of light may be produced for the purpose of giving to the glass article a beautiful and attractive appearance when associated with a lighting fixture or'the like. This desired effect may be obtained by providing a number of pris- Figure 5 is a detailed sectional view of a mould showing the glass body provided with corrugated designs on opposite surfaces thereof and extending in different directions, and

Figure 6 is a detail sectional view showing a glass body, such as a shade or the like, constructed in accordance with the invention and having the surface thereof subjected to the highest temperature in the furnace turned outwardly in the finished glass body, so that the surface having the brightest lustre will be exposed.

In the drawing, 1 designates the bottom of a mould which is surrounded by an edge member 2 of iron or other suitable material. The upper surface of the bottom of the mould has a suitable design which may be in the form of rounded corrugations I, the longitudinal direction of which are at right angles to the direction of the plane of the paper in Figure l. '3 is a glass body formed from a shapeless' mass and which is moulded or pressed down in a plastic state into the form and by means of a suitable tool is made even with the upper side of the edge member 2.

4 is a pressing tool, presenting a design in the shape of corrugations 4'. The corrugations 4' in the pressing tool have different directions than the corrugations l in the bottom of the mould. The to'ol 4 is pressed down into the glass mass 3 so that the same on the upper side receives a:-

design corresponding to the shape of the design 4' of the tool. Th glass body thus pressed has now a uniplanar shape.

In order to give the glass body the-desired cup form or shade shape, the glass is reheated in a furnace so as to become mouldable and then is removed and may be placed in a second concaved shaped mould 5, Figure 4, having the desired cup form. In the mould 5 the plastic glass may be pressed down into the mould by means of a suitable tool without affecting the general shape of the designs. The glass body 3a then assumes the final shape shown in Figure 4. This final shape is such that the corrugations could not be produced by moulding or pressing since the mould Or the pressing tool could not drop the glass body. The glass body manufactured according to the present invention is freefrom marks or irregularities as would arise from a divided mould or a divided pressing tool.

Figure 3 shows the same mould I and the enclosing edge member 2 as in Figure 1, and has the corrugated designs 3' formed in the upper side of the glass body by means of a roller 1 that is provided with annular rounded recesses 6. It will be seen that as the roller 1 moves over the glass 3 and it is subjected to downward pressure, that the corrugations 3 will be formed in the upper surface of the glass body so asto extend in a direction opposite to the corrugated designs.

matic or lens-shaped elements which are stamped into the surface of the glass article to form the particular design, and so arranged that the whole assembly will sparkle and produce a multitude of bright spots of a highly aesthetic and pleasing efiect.

The optical results produced by the improved method of illuminating lighting fixtures in which means are provided for hiding the source of light and yielding an attractive appearance by the lustre or brilliance imparted tothe glass body, may best be obtained by letting the interior and exterior walls'of the lightfixtures form an assembly of strongly curved surfaces. The curvature of each fixture is such that a number of images of the source of light is produced adjacent to the light fixture or inside the same and are visible from outside the fixture. .l The size of these images should be such as not to make themappear as being derived from a source of light. It may be added that their mutual disstance should becalculated in such a manner that they appear as bright points or spots in the glass article or fixture.

When producing a glass body according to the invention, a mould open at the top' may be used for the primary formation (Figure 5) the bottom I of the mould being substantially plane and its lateral edge members 2 that extend around the bottom may be detachable. The height of the lateral edge members 2 will preferablysubstantially correspond to the thickness of the glass body. The bottomof the mould I may have a suitable design !3 in the top surface thereof, and the viscous glass heated to asuitable plastic condition is placed in the mould so thatv the portion of the glass bearing on the bottom of the mould will forma design corresponding to the configuration of the design 53, such as 'a cross, corrugated projections, protuberances or the like. The design or pattern is formed so that the glass body can beremoved in a single piece from the mould and in certain cases, the side edges 2 may be divided in order that the glass body can be removed laterallyfrom the mould.

While the plastic glass body I4 is in the mould, a suitable design 15 may be'pressed or formed on the upper surface of the glass in any suitable manner such as by rollers or a stamping operation. The design. [5 has a considerable height in the embodiment shown in Figure 5, and preferably is formed with rounded corrugations having a main direction different from that of the design or pattern [3 in the bottom of the body. After the designs are formed on opposite sides of the glass body, the latter is removed from the mouldl and introduced into a heating furnace before it has an opportunity to cool down below 350 C. and preferably not below 500 C. Inthis furnace the glass is placed on a suitable bedding such as. a portable plate of sheet iron :perfections,

thic ness siflr nei W est-0,444

and reheated. During this reheating, the upper or exposed surfaoelof itheiglass istsubjected :to a higher temperature than the (lower side resting onthe b'edding, with the-result that anyimsuch .as .fins formed in the exposed surface of Ith'eiglass .duringthe initial formation thereof in the mould l are melted intothe body of the-glass .soas to provide a glossy, brilliantly. exposed outer. surface. The; reheated glass body :is then while.- still resting .011 saidportable iron plate. or; support; removed from. :the furnace when the :upper glossy surface; of: thcpglass has attained a .temperaturebf tat least 3900"; :C;;.and preferably notxmore 5than-1000 .0; Thc.:;formed glass :body: in its plasticheatedrccndition is then transferred irom said platezontc or :templet'andmay beznositione. V y amuitabletooleo ;as;to.;.a.ccurate1yioflow the shape-of: itheemould;and;;without afiectin the desi ns. .onnpposite sides of theglass body. Prefrablyrthe :side of the glass :bodyxwhich has-bee sub e ted to he h est degree oftemperatur inrthe f rnace posit onedon the curv mo l sotha t is side will e urn d o twa dly in t e imshe -e ass dy/and b ause of its e ssya d brilliant appearance will materially enhance the o rrramental characters of the glass body or shade. Since during the rcheating operationin h fu n e a y irregu arities formed: i the surface of the glass body/flow out into the, glass and provide a smooth glossy -surfacerit .will be unnecessary-to subject the, glass body to any mechanical treatment. When the uni- .planar glass body iormed 'ngthe first mound I is taken out from themould the-temperature of the glass has sunkto, .say -for; instance, about 600, C. The temperature of the gl ss is, then too low to permit the uniplanar, lass-body to be bent by means of the second mould 5. It isfor this reason that the laSS reheatedtoa range between 9.09. a .1000; dteierehemgbent to its has drfhichl has :been L 'ShOWnby eneral;exampleinrxlilieure 5; it "ispossibl o distinguish betweenthreerlaycrsrir-e;, the

5. andthe. relas layenoi h between the..;interior portions id si 12s.; It hasbeenioundthatthe thick.-

.taininszthewdesi nes a :should amount to.- =b,etwe.en14rmmrand i ;.;..preferab1y--between 65mm: andiu mm. calcul. ted trues-measures. The dimensionhas; also rascertain-:relationato the:dimerisionof 'heightblforzat least the; design oiione side of the glass. The. dimension .b: should preferablyabe chosenzgr ater:.thanthe dimension-1a,oitemconsiderably reater thanthe latter;

. Ii athe;desigrroi one;sidelis;highior.:has;a:great volume or thickness, the design or the, otherlside 1.3, ,(Figure may,.if-desired be-mcre finely dividedfand closer; the densitrbeihs: dcpendenti n th 'iheisht, as.. :a,: veryzolose:designncannot.:have 'any;considerables heightr Thecclosewfine design willzprimarily. serve, -1.thepurp0se of dis ersing light,.an d-in thiswayahidingthe:sourceofi light that illuminates the fixture-,-..whi-1e;the;=.c0arser dcs snrwhichswill usually beat medbutwards in the bowl orshade; serves, morcgto, give: the. glass itsnspecific lustre; The .design 1on--.atleast one -Sid6s0f the bowl or fixture ispreferablychosen so Ethiclithat the .totaLvolume ofvthe .design portions amountsito-betweemfiO %z: and 200%.; pref- .erably:betweer-r-75i%.:-v and .15Q% .r.oi :thewolume. of

the; glass.-:substancaflocated;betweenztheslowest partsortheidesignon eithersidethereoirfj 2 i c at r-comprising the des n! 3 andrthelayericonglass body .cannot be madebypressingorzcasting inan undivided mould. Furtheniaglossyor shiny surface is :imparted 'to' :thexouter; corrugated design'xby reason of this surfaceabeingsubjected to the higher heat in the-furnace; When 'shaping the glass tothe shape .of Figure 26', .thercorrugations .of the .design 15?), from the mutual. position as :shown. in Figure 5,, have been subjected to .a marked mutual displacement. The displacement is in Figure 6;. designated by-divergin'g: lines. 6, which were parallel .in theaprimaryimouid .body.

The shiny evenisurface which. theglass-obtains through being reheated .in the furnace increases the ornamental effect'of the :glass proper, so that any mechanical treatment :of thefinal glass product can be dispensed 5 with when .the fins are melted into the mass .of the glass body. Moreover, the reheatingof the glass between the treatment in the first mould and :.the:bending operation is necessary since .if: the; glas were allowed to cool before :the intermediate :heating takes place, therewouldbe a risk-of the glass being broken when forming large ;ornamental.fixtures or designs. In practice,- the'glass body 'or shade is made with very strong :corrugateddesignson at least one side thereoLwhilethka opposite side may be'providedwith..a:.f1ner or thin design. By forming the designs onopposite sides of the glass body so as to extend indifferent-directions, a refraction in the:.glass is: obtained which hides or concealsthe source ofr'light and also prevents the light from havinga blinding effect on the spectator., Due tothe reheatingof the glass body in the furnace .so that :one'side thereof is heated to-a temperature :of approximately 1000 C., the entire exposed surface :of the glass body is provided with'a bright,,lustrous, brilliant surface which materially enhances the ornamental and attractive appearance of the fixture. It will be apparent that'thciedges of the glasc body would have an annoying mirror-e'like effect if they were mechanically worked or formed by grinding. Consequently, the. glass body constructed in accordance with the "present method is formed with'unworked edge portions while the fins which are oftenformed at the edges of the glass during'the initial treatment or heating-of the glass in the mould,:are melted into the glass by reheatingthe glass in the furnace to the desired temperatures. 7

It will be understood that the, method for forming the glass articles in accordance with the present invention, is merelyillustrative and that such changes may be made as.v fall within the scope of the following claims.-

I claim;'

1., A; method of producing articles of glass which consists inheating aglassbody .to aplastic state,-; forming designs on opposite sides of the glass :body, theide'sign on one-side ofthe-glass body having different general directions than that onthe opposite side thereof; reheatingthe glass body on a portable plate so that one side-is heated to a higher temperature than the opposite. side and is provided with a glossy 'finish and to. a:-.temperature which causes any fins or thin edgeswformed on the glass" body-to be melt'ed into ithe-zmass :of the 'gl'ass -bodyyandplacingth'e glass body while. carried by theplate and in aplastic state on a curved mould and in'such a manner that the plastic glass body assumes the general shape of the curved mould without affecting the general shape of the designs on the glass body.

2; A method of producing articles of glass as called for'in claim 1 which consists in reheating the glass body to a temperature so that the upper side of the glassbody is heated to at least900 C.

3. A method of producing'articles of'glass which consists in heating a glass body to a plastic state, forming corrugated designs on opposite sides of the glass body, the designs on one side ofthe glass body having different general directions than those on the opposite side thereof, reheating the glass body in a furnace while carried on a portable plate and before the temperature of the glass body falls below 350 C. and so thatthe upper side of the glass body reaches a temperature of at least 900 C. so that any fins or thin edges formed on the glass body when the same is formed in the mould are melted into the mass of the glass body, and then placing the glass body while carried by the plate and in a plastic state on a curved mould and in such a manner that the plastic glass body assumes the configuration of the curved mould without affecting the general shape of the designs thereon.

4. A method of producing articles'of glass which consists in heating a glass body to a plastic state, forming designs on opposite sides of the glass body, the design on one side of the glass body having different general directions than that on the opposite side thereof, reheating the glass body while carried by a portable plate and before its temperature falls below 350 C. so that the upper surface thereof is heated to a higher temperature than its lower surface in order to provide a glossy finish to the upper surface of the glass body, and placing the glass body while carried by the plate and in a plastic state on a curved mould and in such a manner that the plastic glass body assumes the general configuration of the curved mould, the upper glossy surfaceof the glass body being positioned on the curved mould so that the glossy surface forms the outer surface of the glass body.

5.'A method of producing articles of glass which consists in heating aglass body to a plastic state, forming designs on opposite sides of the glass body, the design on one side of the glass'body having different general directions than that on the opposite side thereof, reheating the glass body while carried'by a portable plate and to a temperature between 900 C. and 1000" C. so that the upper surface thereof is heated to a higher temperature than its lower surface in order to provide a glossy finish to the upper surface to the glass body, the reheating of the glass body also causing fins or thin edges formed on the glass body to be melted into the mass of the glass so that the latter is provided with an even surface, and placing the glass body while carried by the plate and in a plastic state on a curved mould and in such a manner that the plastic glass body as.- sumes the general configuration of the curved mould, the upper glossy finish of the glass body being positioned on the curved mould so that the glossy surface forms the outer surface of the glass body.

6. A method of producing articles of glass for lighting fixtures, having reduced transparency and great refractive power, consisting in moulding a plastic mass of glass into a uniplanar glass body having rounded projecting designs on both sides o'f'the glass body, said designs on one side of the glass having different general directions from those on the other side, reheating the glass on' a portable plate and to a temperature above 900 C. so that fins formed. at. the edges of the glass when formed in the mould are melted into the mass of the glass, and placin the glass body while carried by the plate and in a plastic state on a curved shaped mould, whereby to give the glass body its final curved shape departing from said plane shape so that the relative positions of the designs are changed which increases the refractive power of the light but without affecting the general shape ofsaid designs;

'7. A method of producing articles of glass for lighting fixtures, having reduced transparency and great refractive power, consisting in heating a mass of glass to render it plastic, forming the heated glass into a substantially uniplanar body by placing the heated glass on an open mould having confining edges at its circumference and a substantially uniplanar bottom provided with designs running in substantially one direction so as to form corresponding designs on the lower face of the glass body, forming designs on the upper face of the glass, said last-named designs having another general direction than said firstnamed designs, reheating the glass body while supported on a plate and in a furnace before the temperature of the glass bodyfalls below 350 C. to a temperature between 900 C. and 1000- C., and placing the glass body while carried by the plate and in a plastic state on a curved templet to give the glass body a final curved shape departing from said uniplanar shape so that the relative positions of the designs are changed which increases the refractive power of the glass but without affecting the general shape of said designs.

8. A method of producing articles of glass for lighting fixtures, having reduced transparency and great refractive power, consisting in heating a mass of glass to render it plastic, forming the heated glass into a substantially uniplanar body by placing the heated glass on an open mould having confining edges at its circumference and a substantially uniplanar bottom provided with designs running in substantially one direction so as to form corresponding designs on the lower face of the glass body, forming designs on the upperface of the glass body, said last-named designs having another general direction than said first-named designs, heating the glass body while supported on a portable plate and. in a furnace, and thenplacing the glass body while carried by the plate andin a plastic state on a second substantially dish-shaped mould to give the glass body a final curved shape departing from said uniplanar shape so that the relative positions of the designs are changed which increases the refractive power of the light but without affecting the general shape of said designs, the confined edges of the mould imparting a contour to the glass body-that is maintained in the finished curved shaped glass body without mechanical treatment.

9. A method of producing a glass article having reduced transparency and good refraction, which consists in heating a mass of glass to render it plastic, forming the heated glass into a substantially uniplanar body by placing the heated glass on an open mould having confining edges at its circumference and a .substantially uniplanar bottom provided with designs running in substantiallyon'e direction so as toform correspondforming corrugated designs on the upper sur- 7 face of the glass body, the corrugated designs on the upper surface of the glass body extending in a different direction than the designs on the lower surface of said body, removing the glass body-from the mould while hot, reheating the glass body while supported on a portable plate and in a furnace to a temperature above 900 C. and before the temperature of the glass body cools below 350 C. so that the upper surface of the glass body is heated to a higher temperature than the bottom surface thereof in order to provide a glossy finish to the top of the glass body, the reheating of the glass body in the furnace causing fins or thin edges formed on the glass body when the latter is formed in the mould to be melted into the mass'of the glass body,

10. A method according to claim 6 charac said reheating also removing any unevenness of the glass surface by reason of the high terized by the fact that at least part of the design projections are given a height on at least one side of the glass body greater than the thickness of the glass located between the lowest portions of the designs on opposite sides of the glass body.

11. A method according to claim 6 characterizedv by the fact that the glass body is dimensioned in such a manner that the volume of glass forming the design on one side of the glass body amounts to between 50% and 200% of the volume of the glass substance lying between the lowest portions of the designs on either side thereof.

FREDRIK WILHELM ANTON KURZ.

REFERENCES CITED The following references are of record in the file of this patent: 

